Yuri Boykov, Olga Veksler, and Ramin Zabih. Fast approximate energy minimization via graph cuts. IEEE Transactions on Pattern Analysis and Machine Intelligence, 23:2001, 2001.

Tamal Dey, Herbert Edelsbrunner, Sumanta Guha, and Dmitry Nekhayev. Topology preserving edge contraction. geometric combinatorics. Publ. Inst. Math. (Beograd) (N.S.), 66:23–45, 1999.

George Karypis and Vipin Kumar. A fast and high quality multilevel scheme for partitioning irregular graphs. SIAM Journal on scientific Computing, 20(1):359–392, 1998.

Jeremy G. Siek, Lie-Quan Lee, and Andrew Lumsdaine. Boost Graph Library. Addison-Wesley, 2002.